Technetium-99 is produced in high yield (~6%) during the fission of 235U. This long-lived isotope (t1/2 = 212,000 y) presents unique challenges in the reprocessing of spent nuclear fuel and long-term storage. Primarily observed as a tetrahedral oxoanion, 99TcO4- can readily distribute in both the separated metals (Pu, U) and the raffinate in the PUREX process. In an effort to isolate 99Tc from dissolved fuel and the resultant waste streams, a novel surface modified material was specifically developed to selectively remove 99TcO4- from aqueous solutions. Batch separations were conducted to examine the equilibration time for effective 99TcO4- extraction. Quantitative extraction was observed in a short timeframe over a wide concentration range. Competition studies were carried out in the presence of anions (e.g., sulfate, chloride, nitrate) that mimic the high ionic strength of the waste stream. This study confirmed a high selectivity for 99TcO4- over the competing anions. The 99TcO4- extraction was also examined over a broad pH range, which did not impact extraction efficiency. The fast equilibration coupled with selectivity provides a viable new platform for extraction of 99TcO4- from aqueous samples.

Separation of technetium from aqueous media with surface-modified materials

251st National Meeting (2016)

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